Mahogany tree fossil pushes back origin back by 15 to 20 million years

A new study has traced the mahogany family of trees back to the era when dinosaurs vanished. The research shows that the earliest appearance of mahogany in the fossil record was actually 15 to 20 million years earlier than what was previously thought. 

The analysis was conducted by Brian Atkinson, an assistant professor of Ecology & Evolutionary Biology at the University of Kansas.

The findings indicate that the mahogany family originated during the Campanian stage of the Late Cretaceous between 72-79 million years ago. Previously, experts believed that mahogany trees appeared about 60 million years ago during the Paleocene.

The fossil presence of mahogany is significant because it gives scientists an indication of where tropical forests once stood. 

“For understanding when many of the different branches of the tree of life evolved, we’re primarily dependent on the fossil record,” said Professor Atkinson, “In this case, Meliaceae, the mahogany family, is an ecologically and economically important group of trees.” 

“A lot of researchers have used this group as a study system to better understand the evolution of tropical rainforests. This work is the first definitive evidence that the tropically important trees were around during the Cretaceous period, when we first start to see the modernization of ecosystems and modern groups of plants.”

The current investigation was focused on a well-preserved mahogany specimen discovered just off Vancouver Island. 

“The rock that contained the specimen was collected by a local fossil collector, Graham Beard, who is the director of the Qualicum Beach Museum of Natural History,” said Professor Atkinson. “He collected it years ago, but I was actually interested in the rock that has this fossil in it for something else. And as I kept preparing this rock more for the other fossils that were in there, this thing showed up by surprise. So, it was kind of found by accident.”

Professor Atkinson examined the structure of the fossilized fruit and analyzed phylogenetic information to identify the fossil.

“I combined the molecular data from living representatives of the mahogany family with the morphology of the fossil, as well as the morphology of living species. And then I subjugated that combined dataset to phylogenetic analyses, which allows us to reconstruct evolutionary relationships. Based on this analysis, we found the fossil is closely related to this genus called Melia, which is living today.”

The newly described specimen, Manchestercarpa vancouverensis, is now the oldest-known mahogany fossil. Its scientific name represents where the specimen was discovered, and the genus is named to honor one of Professor Atkinson’s colleagues.

“I named it after a prolific paleobotanist who’s really improved our understanding of the evolution of flowering plants through the fossil record. So, I named it in honor of Steve Manchester, who’s at the University of Florida Museum of Natural History.”

The research not only pushes back the origin of mahogany, but also helps to improve our understanding of early flowering plant evolution, according to Professor Atkinson.

“They’re our most diverse group of plants on Earth, and so there’s a whole lot to explore. And there are some cool things you can do methodologically that you might not be able to do with other groups of plants. I can really ask some exciting paleontological and general evolutionary questions with this group.”

The study is published in the American Journal of Botany.

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By Chrissy Sexton, Earth.com Staff Writer